For machines within a manufacturing process to operate properly, these machines require a steady and controlled rate of product coming to them. One of the easiest ways to accomplish this is to accumulate product on a conveyor behind some type of gating mechanism. Holding product behind a physical gate, however, allows the conveyor to slide under the back log of product, and each product creates more pressure on the products in front of it. Some products can not tolerate this pressure or in the case of some soft or sticky products can not stand any product to product contact.
Previous attempts at solving the problem of a physical gating mechanism and the associated backlog pressure use a system composed of a receiving conveyor and a discharge conveyor connected by a moving transfer point. The receiving conveyor runs faster than the discharge conveyor. Therefore, products on the receiving conveyor will catch up to products on the discharge conveyor. The moving transfer point is located directly behind the last product on the discharge conveyor and follows this product as it moves forward. Just as a product on the receiving conveyor is catching up with the last product on the discharge conveyor, the moving transfer moves back to create a space on the discharge conveyor for this products and starts following the new last product. A disadvantage of this system is that in addition to the moving transfer, a moving support for the receiving and discharge conveyors and a system to take up and let out the belts as the transfer moves are required. This adds to the inertia load every time the moving transfer changes acceleration.